/* -*-c++-*- */
/* osgEarth - Geospatial SDK for OpenSceneGraph
 * Copyright 2020 Pelican Mapping
 * http://osgearth.org
 *
 * osgEarth is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>
 */
#ifndef OSGEARTHUTIL_MGRS_GRATICLE
#define OSGEARTHUTIL_MGRS_GRATICLE

#include <osgEarth/Common>
#include <osgEarth/VisibleLayer>
#include <osgEarth/StyleSheet>
#include <osgEarth/Feature>
#include <osgEarth/LayerReference>
#include <osg/ClipPlane>

namespace osgEarth { namespace Util
{
    /**
     * Implements a MGRS (Military Grid Reference System) map graticule. 
     * 
     * NOTE: So far, this only works for geocentric maps.
     * TODO: Add projected support; add text label support
     */
    class OSGEARTH_EXPORT MGRSGraticule : public VisibleLayer
    {
    public: // internal serialization data
        class OSGEARTH_EXPORT Options : public VisibleLayer::Options
        {
        public:
            META_LayerOptions(osgEarth, Options, VisibleLayer::Options);
            OE_OPTION(URI, sqidData);
            OE_OPTION(bool, useDefaultStyles);
            OE_OPTION_LAYER(StyleSheet, styleSheet);
            virtual Config getConfig() const;
        private:
            void fromConfig(const Config& conf);
        };

    public:
        META_Layer(osgEarth, MGRSGraticule, Options, VisibleLayer, MGRSGraticule);
        
        //! Location of the SQID feature data
        //! This is a prebuilt binary file that you should distribute 
        //! with the application - typically names "mgrs_sqid.bin"
        void setSQIDDataURL(const URI& value);
        const URI& getSQIDDataURL() const;

        //! Styles for each display level. Each level should be names in the
        //! following manner:
        //! The top-level grid zone designator is called "gzd".
        //! Each consecutive level is a power of 10, starting with "100000"
        //! (for the SQID 100km grid) and going down from there (10000, 1000, etc.
        //! down to level 1).
        //! You can set only certain levels if you wish in order to override
        //! the defaults.
        void setStyleSheet(StyleSheet* value);
        StyleSheet* getStyleSheet() const;

        //! Whether to apply default styles when you do not expressly
        //! set them for all levels. Defaults to true.
        void setUseDefaultStyles(const bool& value);
        const bool& getUseDefaultStyles() const;

        //! If you change any of the options, call this to refresh the display
        //! to refelct the new settings.
        void dirty();

    public: // Layer

        virtual Status openImplementation();

        virtual void addedToMap(const Map* map);

        virtual void removedFromMap(const Map* map);
        
        virtual osg::Node* getNode() const;

        virtual void init();

        virtual Config getConfig() const;

    protected:

        /** dtor */
        virtual ~MGRSGraticule() { }


    private:
        
        void setUpDefaultStyles();

        void rebuild();

        osg::ref_ptr<const Profile> _profile;

        osg::ref_ptr<FeatureProfile> _featureProfile;

        osg::ref_ptr<osg::Group> _root;

        osg::observer_ptr<const Map> _map;

        void loadGZDFeatures(const SpatialReference* srs, FeatureList& output) const;

        typedef std::map<std::string, osg::ref_ptr<osgText::Text> > TextObjects;
        TextObjects _textObjects;
    };

} }

#endif // OSGEARTHUTIL_UTM_GRATICLE
